Typewriting machine



Nov. 25, 1941. w. F. HELMOND TYPEWRITING MACHINE 2 Sheets-Sheet l Filed June 22, 1939 INVENTOR l h//LL/AM HELMOND NOV. 25, 1941.- W. F. HELMOND TYPEWRITING MACHINE 2^Sheets-Sheet 2 Filed June 22, 1939 Patented Nov. 25, 1941 UN!! TED STTES -orricr TYPEWRI'I'ING MACHINE AppiicationJune 22, 1939, SerialNo.`28`0,52l5

(Cl. V19V-373) 4 Claims.

This invention relates to typewriting machines and, with regard to certain more specific features thereof, to case-shifting devices vparticularly of the character in which electromagnetic means is employed in the operation of 'shifting from one'ca'se-typing position to another. In certain respects 'the 'invention is an improvement vupon that-shown and'described'in my-copending application Serial No. 280,546, led June 22, V1939.

mechanism.

Fig. 2-is ta View similar to Fig. llbut illustrating the parts in vupper-case typing position assumed when the case-shift lkey is depressed.

Fig. 3 is a fragmentary view in perspective of the latching mechanism and Aa portion of the control for the electromagnetic means.

Fig. 4 is --a fragmentary plan view showing a portion of the control means for the electric motor and the driving connections from the .motor to the case-shift frame.

VReferring now more in detail to the drawings, a typewriter frame is indicated generally at YIl). It has conventional side walls -one of which is indicatedat -ll and -a rear wall l2. The typewriter carriage is indicated generally Aat |3 mounted for transverse movement von a `Way rod I4. The typewriter carriage frame is shown at l-5 and between end walls of this frame, one of which is shown at i6, a shaft ill is mounted having a lift hook I8 at each end. The l-ift hooks take under pins 23 of a movable skeleton 2l which is also pivotally connected tothe carriage frame by end links V2-2.

A roller platen -23 is'suitably journaled in the skeleton and the latter has a roll bearing on a case-shift part or .frame 24 as indicated at 25. An adjustable stop 23 is arranged -in the path of a shoulder 2 of the skeleton to variably limit the movement of the latter to upper-case typing position.

The shift frame 24 comprises opposite end members 28 and 33 connected by a cylindrical rod 3l. The end members are xed upon a shaft 32 suitably journaled inthe side walls of the lmain frame of the typewriter The left-hand end member 28 of the shift frame has a laterally extending pin-33 projecting into an aperturei34 at the end of a lever 35 -pivotally Vmounted. on the frame by a shoulder screw 35. The forward end of lever 35 has an ear'31 underlying an arm 38 of a case-shift key-lever 4G fixed on the shaft 4l which vlatter is journaled in the side walls of the frame. A right-hand case-shift key-lever is shown in Fig. 3 at 42 also Xed von shaftM.

Upon a :transverse bar or backbone 43 of the main frame there is fixed a bracket i4 .journaling a short :rock-shaft 45 which latter has a lfixed arm A6 the upper end'of which is pivotally connected at 4l to -a link -48 and theother end of which is pivotally connected-at 53 to the lefthand case-shift key-lever 43. A spring 5I, having one end connected :to bracket 44 and the other end to link 13.3, normaliy :urges the link rearwardly and thecase-sl-iift lever 43 counterclockw'ise. This movement -is limited by a stop :lug 5-2 of lever B3 abutting a comb plate 53 fixed tothe frame of .the machine. Spring 5I `thus determines the normal or undepressed position of case-shift keys 54 and 55^of levers 40 and 42 respectively. A torsion spring v53 tends to hold lever 35 with its rear end depressed to encompass -pin 33 of the case-shift member within a latch portion 51 of aperture 34. Thus the lower-case position of the case-shift vframe is `determined and `maintained until one of keys 5ft or 55 is depressed, whereupon arm 38 urges -ear 31 downwardly to raise the rear end of lever 35 against the action of spring 53 and withdraw latch portion -51 from the pin 33.

A coil spring 63 has one end anchored to the main frame at 6| and its other end attached to end member v2-8 of the case-shift frame at 462. Thus as either key is depressed and pin 33 is released spring will swing lcase-shift frame 24 counter-clockwise, as viewed in Figs. l and 2, raising the cylindrical rail 3l and 'lifting skeleton 2l and platen roller `23 until stop 26 is engaged by shoulder 2l of the skeleton.

An electric motor is indicated at B3 and has an armature shaft 36 upon which are xed spaced collars and 53. Adjacent collar `65 is a friction disk 31 and next to that a pulley 68 loose upon the shaft 54. On the other side of the pulley is a disk I0 of friction material faced with a loose metal collar ll. A coil spring 72 compressed between collars -63 and 1l develops a surface friction sucient to rotate pulley 33 with the armature shaft 64 and provides for lslip in vthe drive when a suitable resistance to the movement of case-shift part 24 is developed.

A belt 13 has one end fixed to pulley 68 and, after passing around an idler pulley 14 mounted on a bracket 15 on cross bar 43, its other end is attached at 16 to an upper part of the case-shift frame 24 near the rail 3|. It will be seen that energization of the motor 63 to rotate its armature shaft in a clockwise direction, as viewed in Figs. 1 and 2, will wind the belt on pulley 68 and move case-shift frame 24 clockwise on its shaft pin 32 thus dropping rail 3| and allowing the skeleton and platen to follow. The friction developed by spring 12 plus gravity effect is sucient to expand or reenergize spring 68 and position pin 33 where it may be latched by lever 35.

At the rear of the machine is a motor control box and motor supporting bracket 11 having several inwardly projecting posts 18 upon which is mounted a vertical plate 88 faced with an insulating plate 8|. Along the face of insulating plate 8| is a metal strip 82 of electrical conductivity carrying a fixed contact 83. A yoke 84 extends forwardly from the insulating plate 8| and serves to pvot at 85 a lever 86 carrying at one end a contact 81 engageable with the fixed contact 83. Lever 88 has a depending tail 88 against which an arm 98 fixed on the case-shift frame 24 at 9| bears when the frame is in its latched lower-case typing position. A leaf spring 92 having its lower end fixed to insulating plate 8| bears against the opposite side of tail 88 and tends to urge contact 81 into engagement with contact 83 when the case-shift frame is moved to upper-case typing position by spring 89. This engagement is temporarily prevented, however, by a shoulder 93 on a link 94 engaging a portion 95 of an insulating strip 96 which depends from the contact carrying side of lever 86. Link 94 has its forward end pivotally connected at 91 to an arm 98 fixed on rock shaft 45 and the rear end of the link passes through slots in insulating strip 96, insulating plate 8| and vertical metal plate 88. The link is recessed to provide the shoulder just described and normally this shoulder is somewhat to the rear of insulating strip 96.

Thus when either of the case-shift keys is depressed link 48 is drawn forwardly rocking shaft 45 and drawing forwardly the link 94 so that when the latch pin 33 has been released and the case-shift part 24 swung by spring 68 to remove arm 98 from contact carrying lever 86, the shoulder 93 will engage portion 95 of insulating strip 96 and withhold the contacts from engagement against the action of leaf spring S2. This condition will be maintained as long as either caseshift key is held depressed but when the key is released and is on its return to normal position link 94 will move rearwardly allowing leaf spring 92 to cause engagement of contacts 81 and 83 whereupon the electric motor will be energized through suitable circuit connections, including the contact pair 83-81, and move the case-shift frame clockwise, as viewed in Figs. 1 and 2.

By reference to Fig. 2 of the drawings it will be seen how link 94 maintains the Contact pair separated during the depression of the case-shift key. It will also be obvious from this figure that the case-shift key may be well on its way back to normal position before the contacts are engaged. Shortly before the point of full return of the case-shift frame to normal or lower-case typing position, the arm 98 again picks up tail 88 of contact-carrying lever 88 and moves it against the opposition of leaf spring 92 to disengage the contact pair 81-83. Weight of the parts and momentum continue the stressing of spring 68 and the movement of the case-shift frame 24 to its limit of movement determined by engagement of the pin 33 with the end of aperture 34 in lever 35, at which time spring 56 will snap the latch portion 51 of the lever into position over the pin. Fig. 1 of the drawings shows another shouldered link |88 for controlling another contact pair IUI-|82, the action of which need not be considered for the purposes of the present case.

Conventional case-shift-lever locking means (not shown in the drawings) may be employed for maintaining the case-shift frame in uppercase typing position.

By the mechanism herein described the electric motor circuit controls are simplified over the controls shown and described in my copending application hereinbefore referred to. The shifting of the case-shift frame to upper and lower case typing positions is more direct and speedier than in the mechanism of said copending application, and short pivoted key levers may be employed for controlling the shift action in both directions.

What is claimed is:

1. In a typewriter, a case-shift mechanism comprising, a part to be shifted, spring means for moving said part in one direction, an electric motor for moving said part in the opposite direction, an electric circuit including said motor and a pair of contacts urged to engage, means on the part to be shifted normally holding said contact pair separated, a latch-lever normally holding the part to be shifted against the action of said spring means, a key-lever for operating said latch-lever to release said part to the action of the spring means, a draw-rod connected with said key-lever, having a portion adapted to prevent engagement of said contact pair when the key-lever is moved in one direction to cause release of said part and permitting engagement of said pair to energize said motor when said part has shifted and the key-lever is moved in the opposite direction, and means connecting said motor with said part to move the latter in opposition to said spring means.

2. In a typewriter, a case-shift mechanism comprising, a part to be shifted, spring means for moving said part in one direction, a latch normally holding said part against the action of said spring means, an electric motor, means connecting said motor to said part to move the part in the Opposite direction comprising a friction drive device and a belt extending from said device to said part to be shifted, a controlling key, means responsive to the movement of said key in one direction for releasing said latch, and means responsive to the movement of said key in the opposite direction for rendering said motor effective.

3. In a typewriter, a case-shift mechanism comprising, a part to be shifted, a key, means operative upon movement of said key to shift said part in one direction, an electric motor for shifting said part in the opposite direction, and controlling means for said electric motor including a normally open electric circuit, a lever having a contact for closing said circuit, spring means urging the lever in circuit closing direction, a member on the part to be shifted normally engaging said lever to hold it against the action of said spring means, and a draw bar connected to said key normally ineffective on said lever but adapted with lost motion to act on said lever to when the said part is shifted pursuant to movement of said key, and spring means for restoring said key upon its release and moving said draw bar to release said lever and allcW circuit closing by said contact.

4. In a typewriter, a case-shift mechanism comprising, a part to be shifted, a key, means operative upon movement of said key to shift said part in one direction, an electric motor for shifting said part in the opposite direction, controlling means for said electric motor including a normally open electric circuit, a lever having a contact for closing said circuit, spring means urging the lever in circuit closing direction, a member on the part to be shifted normally engaging said lever to hold it against the action of said spring means, and a draw bar connected to said key normally ineffective on said lever but adapted with lost motion to act on said lever to prevent closing of the circuit by said contact when the said part is shifted pursuant to movement of said key, spring means for restoring said key upon its release and moving said draw bar t0 release said lever and allow circuit closing by said contact, and means for automatically latching the part to be shifted when the circuit is closed, the motor energized, and the said part shifted in the opposite direction.

WILLIAM F'. HELMOND. 

